It occurred within weeks of the deliberate detonation of a waste container in Seaside Park, leading to speculation of a second homemade bomb, terrorism,pranksters or copycats, and an elevated discussion of soft targets.

The blast occurred on quiet Village Drive at about 1:30 AM on Oct. 13. Investigators said the rubber container was reduced to shards, and debris flew in about a 10-yard radius. There were no injuries or property damage.

Analyst Shoshanna Hayesaha of the Bureau of Alcohol, Tobacco, Firearms and Explosives determined that no synthetic materials were involved, though information from the prosecutor's office stops short of pinpointing the composition.

According to Hayesaha, the most likely source is a confluence of rotting mulch, sticks and other organic debris in the enclosed space that developed heat, and ultimately caused an endothermic reaction.

The Seaside Park incident, just before a charity race, was tied to an explosion in Manhattan, for which Ahmad Rahimi faces charges in New Jersey and New York.